Java JPA&x2B；冬眠+；Maven+；NetBeans=HTTP状态500

几天来我一直在想办法，但今天我放弃了。我在尝试创建实体管理器工厂时遇到HTTP状态错误

完整堆栈跟踪：

Type Exception Report

Message Error processing webservice request

Description The server encountered an unexpected condition that prevented it from fulfilling the request.

Exception

javax.servlet.ServletException: Error processing webservice request
    org.apache.tomee.webservices.CXFJAXRSFilter.doFilter(CXFJAXRSFilter.java:98)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)

Root Cause

<openjpa-3.0.0-r422266:1833209 fatal user error> org.apache.openjpa.persistence.ArgumentException: The persistence provider is attempting to use properties in the persistence.xml file to resolve the data source. A Java Database Connectivity (JDBC) driver or data source class name must be specified in the openjpa.ConnectionDriverName or javax.persistence.jdbc.driver property. The following properties are available in the configuration: "org.apache.openjpa.jdbc.conf.JDBCConfigurationImpl@393fa2d". 
    org.apache.openjpa.jdbc.schema.DataSourceFactory.newDataSource(DataSourceFactory.java:71)
    org.apache.openjpa.jdbc.conf.JDBCConfigurationImpl.createConnectionFactory(JDBCConfigurationImpl.java:850)
    org.apache.openjpa.jdbc.conf.JDBCConfigurationImpl.getDBDictionaryInstance(JDBCConfigurationImpl.java:603)
    org.apache.openjpa.jdbc.meta.MappingRepository.endConfiguration(MappingRepository.java:1520)
    org.apache.openjpa.lib.conf.Configurations.configureInstance(Configurations.java:533)
    org.apache.openjpa.lib.conf.Configurations.configureInstance(Configurations.java:458)
    org.apache.openjpa.lib.conf.PluginValue.instantiate(PluginValue.java:122)
    org.apache.openjpa.conf.MetaDataRepositoryValue.instantiate(MetaDataRepositoryValue.java:68)
    org.apache.openjpa.lib.conf.ObjectValue.instantiate(ObjectValue.java:83)
    org.apache.openjpa.conf.OpenJPAConfigurationImpl.newMetaDataRepositoryInstance(OpenJPAConfigurationImpl.java:1035)
    org.apache.openjpa.conf.OpenJPAConfigurationImpl.getMetaDataRepositoryInstance(OpenJPAConfigurationImpl.java:1026)
    org.apache.openjpa.kernel.AbstractBrokerFactory.makeReadOnly(AbstractBrokerFactory.java:643)
    org.apache.openjpa.kernel.AbstractBrokerFactory.newBroker(AbstractBrokerFactory.java:203)
    org.apache.openjpa.kernel.DelegatingBrokerFactory.newBroker(DelegatingBrokerFactory.java:154)
    org.apache.openjpa.persistence.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:246)
    org.apache.openjpa.persistence.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:162)
    org.apache.openjpa.persistence.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:152)
    org.apache.openjpa.persistence.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:58)
    dao.Dao.getUser(Dao.java:15)
    tk.spartan.controller.GetUser.list(GetUser.java:35)
    sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    java.lang.reflect.Method.invoke(Method.java:498)
    org.apache.openejb.server.cxf.rs.PojoInvoker.performInvocation(PojoInvoker.java:43)
    org.apache.cxf.service.invoker.AbstractInvoker.invoke(AbstractInvoker.java:96)
    org.apache.cxf.jaxrs.JAXRSInvoker.invoke(JAXRSInvoker.java:193)
    org.apache.cxf.jaxrs.JAXRSInvoker.invoke(JAXRSInvoker.java:103)
    org.apache.openejb.server.cxf.rs.AutoJAXRSInvoker.invoke(AutoJAXRSInvoker.java:68)
    org.apache.cxf.interceptor.ServiceInvokerInterceptor$1.run(ServiceInvokerInterceptor.java:59)
    org.apache.cxf.interceptor.ServiceInvokerInterceptor.handleMessage(ServiceInvokerInterceptor.java:96)
    org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:308)
    org.apache.cxf.transport.ChainInitiationObserver.onMessage(ChainInitiationObserver.java:121)
    org.apache.cxf.transport.http.AbstractHTTPDestination.invoke(AbstractHTTPDestination.java:267)
    org.apache.openejb.server.cxf.rs.CxfRsHttpListener.doInvoke(CxfRsHttpListener.java:253)
    org.apache.tomee.webservices.CXFJAXRSFilter.doFilter(CXFJAXRSFilter.java:94)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)

所以我现在有点困惑。我一直在寻找这种错误，但我没有找到解决办法

可能是什么

增加：

@Path("user")
public class GetUser 
{
    @GET
    @Produces(MediaType.TEXT_PLAIN)


    public List<User> list ()
            {

    Dao dao = new Dao();
    User user = new User();


    List<User> userListed = dao.getUser(user);


    return userListed;
            }

@Path（“用户”）
公共类GetUser
{
@得到
@生成（MediaType.TEXT\u PLAIN）
公开名单（）
{
Dao=新Dao（）；
用户=新用户（）；
List userListed=dao.getUser（用户）；
返回用户列表；
}

---

我认为应该在jar依赖项（pom.xml）中包含mysql驱动程序。

---

错误消息说：驱动程序未知。

可能会对您有所帮助。您发布了Hibernate的持久化单元，但您使用的是OpenJPA（在例外情况下），因此可能您实际指向了错误的持久化单元（定义如何调用持久化单元，

persistence.xml

存储在哪里，等等…从

tk.spartan.controller.GetUser.list（GetUser.java:35）

开始）。请发布一致的信息。我添加了类GetUser和项目结构

package beans;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name = "user")

public class User {

    @Column(name = "iduser")
    @Id
    private Integer iduser;

    @Column(name = "user")
    private String user;

    @Column(name = "password")
    private String password;

    @Column(name = "role")
    private String role;

    public User() {
    }

    public User(int iduser, String user, String pass, String role) {
        this.iduser = iduser;
        this.user = user;
        this.password = password;
        this.role = role;
    }

    public User(Integer iduser) {
        this.iduser = iduser;
    }

    public Integer getIduser() {
        return iduser;
    }

    public void setIduser(Integer iduser) {
        this.iduser = iduser;
    }

    public String getUser() {
        return user;
    }

    public void setUser(String user) {
        this.user = user;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getRole() {
        return role;
    }

    public void setRole(String role) {
        this.role = role;
    }

}

@Path("user")
public class GetUser 
{
    @GET
    @Produces(MediaType.TEXT_PLAIN)


    public List<User> list ()
            {

    Dao dao = new Dao();
    User user = new User();


    List<User> userListed = dao.getUser(user);


    return userListed;
            }